1. Field of the Invention
The present invention generally relates to computer software. More specifically, the present invention relates to a computer aided design (CAD) application configured for choosing a color to be used by the designer.
2. Description of the Related Art
The term computer aided design refers to a broad variety of computer-based tools used by architects, engineers, animators, video game designers, and other graphics and design professionals. CAD applications may be used to construct computer models or drawings representing virtually any imaginable construct. Commonly, CAD applications utilize colors to compose a visually-pleasing scene or image. A CAD application generally includes a color palette or color wheel from which a user of the CAD application may choose a color to work with. Colors can then be applied to almost any object within the computer model or drawing. Graphical design programs and photo/video editing software tools provide similar features.
A common feature of CAD applications is the ability to “pick” a color from a pixel that appears on the screen. Most commonly, the tool used for this feature is an “eyedropper” and is often referred to as the “color picker.” Generally, a user chooses a color selection tool from a list of available tools. The user then uses a human interface device, e.g., a mouse, to move the eyedropper to a pixel on the screen that represents the color the user would like to choose. Selecting a pixel, e.g., by left-clicking with the mouse, selects the pixel immediately below the eyedropper and sets the color value associated with that pixel as a currently selected color. The currently selected color may then appear in a color dialog box. The user of the CAD application may then apply the selected color to objects in the CAD drawing.
Additionally, the color picking feature may provide a color preview window. For example, the user may choose the color picker tool and move the mouse to an area of the screen where a desired shade of green appears. A color preview window may display to the user what color would be selected at each pixel as the user moves the mouse around the screen. The color preview window may be useful for a user who wishes to select a specific shade of a color from a region of the screen that has a variety of shades of that color. For example, in a CAD drawing depicting a forest, a user may wish to select a specific shade of green.
However, choosing a desired color has proven to be challenging. Prior art techniques for color picking generally only allow a user to select the color associated with one pixel on the screen. Other prior art techniques allow for the selection of a 3×3 or 5×5 pixel matrix, where the selected color is an average color of all the pixels in the pixel matrix. Both of these prior art techniques rely on “point sampling,” where each selection is independent of other selections. These prior art approaches often result in a user having to select, by trial and error, multiple colors from the screen until the desired color is achieved.
Furthermore, it is sometimes impossible to pick the desired color because the color simply does not exist in the image on the screen. Many differently colored pixels, when viewed as a whole, may appear as one color, but when a user is trying to select a color that represents the general impression of a region, no pixel in the region may actually provide the desired color.
While these techniques work as intended, they have a significant limitation in that the color selection tool only allows users to perform a point-sampling, where the selection is based on a single pixel or a small grid of pixels. That is, each action of selecting a color using the tool is independent of one another. Frequently, users do not pick their desired color, but something “close.” In such a case, the user can either pick another pixel using the color sampling tool or adjust the RGBA values in an attempt to create the desired color.
Accordingly, there remains the need in the art for a technique for selecting a desired color using a color selection tool.